Fixed << operator for layers to use universal references and perfect forwarding: now it should really use a move constructor if the specific layer has one.
Fixed << operator for layers to use universal references and perfect forwarding: now it should really use a move constructor if the specific layer has one.

Wangyida/tiny-cnn,H4kor/tiny-cnn,zhangqianhui/tiny-cnn,Wangyida/tiny-cnn,H4kor/tiny-cnn,zhangqianhui/tiny-cnn